Those who eat the fruits provided by the great bounty of the forest generally do not suffer any maladies for doing so. On some occasions, certain found specimens of berry and mushroom may prove to be poisonous, but generations of trial and error have determined which is which. All that is required is the knowledge of certain tell-tale signs, often handed down through oral tradition or the written word and illustration. Know what to look for, and you’ll be well-equipped to harvest edible flora as you pass through the forest.
Generally, the forest is happy to provide such sustenance because those who require it are considered honored guests. It is not unlike those who visit a stately manor being attended to by servants bearing bits of cheese, cured meats, and other hors-d'oeuvres. However, certain areas of the Twelve Great Forests are off-limits: divine cradles of pure, unmolested nature from the primordial days of the Earth. They are not the domain of mankind and you will find no welcome there. Indeed, what I will call the Primeval Gardens are barely known by any living humans at all.
But the average traveler need not worry, for the Great Forests have in place ancient enchantments as old as the Earth itself. No one can accidentally stumble upon a Primeval Garden without pure luck dictating that they miss it entirely. Much like one magnet repelling another of similar polarity, the human explorer is driven away from those hallowed sites and is never the wiser for it.
Occasionally, however, wizards just have to come along and fuck things up.
A wizard is nothing if not a surveyor of loopholes in the contract that humanity has with reality. Even learning of the protective wards guarding the Primeval Gardens is a remarkable feat in itself. Yet, through any of an infinite number of incomprehensible magical means, it is sometimes possible to break through the enchantment and actually set foot on that sacred ground.
However, although the enchantments can occasionally be broken temporarily, absolutely no magic that any living being can channel will obscure the actions partaken by the offending wizard—or their companions—from the Great Forest's Watcher. Awakened by any disturbance in the primeval enchantment, the omniscient Watcher records all deeds—and especially misdeeds—performed until the offender is once again outside the sphere of the enchantment's domain. However, as the Watcher is omniscient but not omnipotent, She will inform any offenses immediately to the appropriate Enforcers.
Enforcers comprise a wide variety of magical entities who are eternally bound in service to the Great Forest itself. Earth elementals, ancient demigods, and even certain legendary animals can be Enforcers, depending on what offense has occurred and if any Earthly magic has been removed or corrupted. The primary goal of an Enforcer is to restore balance to the Primordial Garden by any means necessary. I don't have to tell you that, depending on the nature of the disruption, the act of restoring balance can be... unpleasant.
However, there is a curious case that arises when an intruder actually eats something from the Primordial Garden. Once any fruit, herb, or other food is consumed orally, its magical essence does not transfer to the consumer, or live in their gut somehow. Instead, without fail, it is transferred to the teeth upon chewing. There it will lie forever dormant, unusable even by a wizard. The only means of reclaiming the Garden's essence that was lost is to extract the teeth. And seeing as how no one would risk a direct assault on a wildly unpredictable human wizard—or one of their friends—by removing a set of teeth by force, the Enforcers in such cases are Tooth Faeries.
Tooth Faeries are well acquainted with the neurological workings of human nervous systems, such that ensuring they stay asleep for a complex, painful surgical procedure is no challenge. In fact, they are such skilled Enforcers that they can harvest a full set of teeth and install a nearly identical replacement set in just under two hours. When the subject wakes in the morning, the most they will ever know is that they taste a hint of blood and perhaps a bit of an aching jaw. These symptoms usually pass within an hour. In truth, Tooth Faeries are some of the most effective Enforcers ever to serve the Watchers and the Great Forests when establishing balance to the Primordial Gardens.
The problem is that, because they're Fey, they're usually tricksters and perverts.
What follows is a catalogue of the multitude of effects known to befall some victims of Tooth Faerie trickery. I fear the list may be incomplete, but the list below should nevertheless be accurate.
1) The victims may hear sounds previously recorded from the past 24 hours. It is unknown whether the Faeries or someone else in the Primeval Garden is listening via the teeth and playing the sound back, or whether one of the teeth is actually some sort of enchanted stone. However, it is able to transmit the sound via bone conduction through the jaw. No one other than the victim will be able to hear the sound, although the victim will be utterly convinced it is real.
2) The teeth are able to transmit electrical impulses through their roots nerve endings directly to the victim's erogenous zones. Minor muscle spasms can ensue. The Tooth Faeries almost certainly are monitoring the victim in some manor, because every report of this effect has occurred during a socially stressful and public scenario.
3) The teeth can trigger the release enzymes in the digestive tract to disrupt the normal passage of food. Projectile vomiting or diarrhea can occur in extreme cases, although one of the most common reports of this effect is potent flatulence.
4) Assuming they can write, occasionally the victim may find that they are unable to control the content of their writing, transcribing certain nonsense phrases, such as "milk shake" or "chicken man," in an otherwise totally sensible passage. This effect is particularly disruptive to wizards, who must destroy spells in order to transcribe them into a permanent grimoire.
5) With some sort of monstrous shock to the nervous system, the victim loses all control of their muscles and falls prone for a period of up to two minutes. This is seemingly rare, but particularly dangerous. For example, death can befall anyone crossing a shallow stream or riding their horse at a galloping speed. It could be the case that victims simply don't live in order to report it.
6) For some victims, saliva production temporarily magnifies at least ten fold. This is such a massive increase that the victim must slobber excessively or else choke to death. An additional concern for these victims is drinking enough to prevent lost fluids.
7) Some victims report that their sense of taste is randomized. Savory foods are instead sweet, sweet foods are sour, and so on.
8) As 7, but instead the sense of smell.
9) A limited symptom, but victims reported that they were unable to keep their teeth from chattering loudly once they found themselves in a situation which demanded silence, such as passing a sleeping baby or dog.
10) Occasionally the teeth will simply fall out after a time. It is unknown whether this is intentional trickery or just shoddy work on the part of the Tooth Faeries.
Sadly, while most victims have eventually reported that the above maladies eventually cease, it is unknown what eventually gets the Tooth Faeries to stop. Based on the patterns I have studied thus far, it is quite possible that they give up once another person finds and eats something from the Primeval Garden. Or maybe they just get bored, choosing a different mischief in which to partake. It is my intention to investigate this matter further; perhaps I can find a wizard and some unwitting test subjects.